There is adequate due process, in this case subpoena, for a rights holder to make service on a privacy advocate; just sue the defendants as John Does and serve the complaint registered mail on the privacy advocate along with a subpoena for lifting the veil of privacy on the domain.
The privacy advocate will roll over on the location and the identity of the domain holder in a New York second.
This is about intimidation and prior restraint of unprotected speech by MarkMonitor, et al. who would have remedy for their clients, and if the trademark infringement is that big of a deal, their clients can afford the legal costs.
These domain privacy safeguards and rules are there for a purpose: protecting anonymous speech and preventing harassment -- private registration is being misused as a shield for trademark infringement.
This is no different than anyone being able to get the name of the registered owner and his address from a vehicle's licence plate without cause.
Legal Protections for Anonymous Speech | Digital Media Law Project